DC1640A - Demo Manual

DEMO MANUAL DC1640A
LTC3833EUDC High
Efficiency Step-Down
DC/DC Converter
DESCRIPTION
Demonstration circuit 1640A is a 1.5V/20A synchronous
buck converter operating with a switching frequency of
300kHz over an input voltage range of 4.5V to 14V. The
demo board comes in two versions. The A version uses
inductor DCR current sensing with an iron powder inductor
for high efficiency. The B version uses a 2mΩ /1% sense
resistor for accurate current sensing with a low DCR ferrite
inductor. The fixed on-time valley current mode topology
of the LTC3833 allows for a fast load step response (see
Figures 4 and 5). The load step response can be tested with
the onboard load step circuit and a bench pulse generator.
Other features of the board include a MODE jumper to
program either DCM or CCM with light or no load, a PLLIN
input for synchronizing the converter to an external clock,
a TRACK/SS pin, a PGOOD pin and an EXTVCC pin.
The demo board uses a high density, two sided drop-in
layout. The entire converter, excluding the bulk output and
input capacitors, fits within a compact 1.4” × 0.6” area on
the board. The package style for the LTC3833EUDC is a
3mm × 4mm 20-lead QFN with an exposed ground pad.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
PARAMETER
(TA = 0°C to 85°C)
CONDITION
VALUE
Minimum Input Voltage
4.5V
Maximum Input Voltage
14V
Output Voltage
IOUT = 0A to 20A
Switching Frequency
Efficiency
DCR Sense Version (A)
RSENSE Version (B)
1.5V ±2%
300kHz
VIN = 12V, VOUT = 1.5V, IOUT = 20A; See Figures 2 and 3
89.4%
88.8%
dc1640af
1
DEMO MANUAL DC1640A
QUICK START PROCEDURE
Demonstration circuit 1640A is easy to set up to evaluate
the performance of the LTC3833EUDC. Please refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below.
1.With power off, connect the input supply, load and
meters as shown in Figure 1. Preset the load to 0A
and VIN supply to be 0V. Place jumpers in the following
positions:
JP1
JP2
RUN
MODE
ON
CCM
2.Adjust the input voltage to be between 4.5V to 14V.
VOUT should 1.5V ± 2%.
3.Next, apply 20A load and recheck VOUT.
4. Once the DC regulation is confirmed, observe the output
voltage ripple, load step response, efficiency and other
parameters.
Note 1. To measure the output voltage ripple, use the BNC
connector labeled VOUT.
Note 2. Do not apply the load from the VO_SNS+ turret
to the VO_SNS– turret. This will damage the converter.
These turrets are only intended to monitor VOUT across
COUT4 which is the point of regulation.
+
VOUT
V
–
*
IOUT
IIN
A
A
+
VIN
SUPPLY
+
LOAD
–
DC1640 F01
–
VIN
V
+
* THE VO_SNS+ and VO_SNS– TURRETS MONITOR VOLTAGE ACROSS COUT4 WHICH
IS THE POINT OF REGULATION. MONITOR THE VOLTAGE ACROSS COUT2 FOR MORE
ACCURATE EFFICIENCY MEASUREMENTS.
Figure 1. Proper Measurement Equipment Setup
dc1640af
2
DEMO MANUAL DC1640A
QUICK START PROCEDURE
Demonstration circuit 1640A has a simple load step circuit
consisting of a MOSFET and sense resistor. To apply a load
step, follow the steps below.
1.Preset the amplitude of a pulse generator to 0.0V and
the duty cycle to 5% or less.
2.Connect the VOUT and LOAD STEP BNC connectors to
the oscilloscope. Use a short cable to minimize noise
pickup.
3.Connect the output of the pulse generator to the PULSE
GEN turret and connect the return to the GND turret.
4.With the converter running, slowly increase the amplitude of the pulse generator output to provide the desired
load step pulse height. The scaling for the LOAD STEP
signal is 10mV/Amp.
95
100
90
DCR SENSE
90
80
85
80
DCR SENSE VERSION (–A):
L = WÜRTH 744355047
(0.47µH, DCR = 0.9mΩ ±10%)
75
RSENSE VERSION (–B):
L = COILTRONICS FP1308R3-R44
(0.44µH, DCR = 0.18mΩ ±20%)
RSENSE = 2mΩ
70
EFFICIENCY (%)
EFFICIENCY (%)
RSENSE
QTOP = RENESAS RJK0305DPB
QBOTTOM = RENESAS RJK0330DPB
0
5
10
15
LOAD CURRENT (A)
20
70
60
RSENSE DCM
RSENSE CCM
50
40
DCR SENSE VERSION (–A):
L = WÜRTH 744355047
(0.47µH, DCR = 0.9mΩ ±10%)
DCR SENSE DCM
30
20
10
25
DC1640 F02
Figure 2. Efficiency Curves for the DC1640A in CCM.
0
0.01
DCR SENSE CCM
0.1
QTOP = RENESAS RJK0305DPB
QBOTTOM = RENESAS RJK0330DPB
RSENSE VERSION (–B):
L = COILTRONICS FP1308R3-R44
(0.44µH, DCR = 0.18mΩ ±20%)
RSENSE = 2mΩ
1
LOAD CURRENT (A)
10
100
DC1640 F03
Figure 3. Efficiency Curves for the DC1640A in CCM and DCM.
dc1640af
3
DEMO MANUAL DC1640A
QUICK START PROCEDURE
50µs/DIV
1.5VO (AC)
50mV/DIV
LOAD STEP
10A/DIV
50µs/DIV
1.5VO (AC)
50mV/DIV
20A
LOAD STEP
10A/DIV
10A
DC1640 F04
Figure 4. 10A to 20A to 10A Load Step Response of the
DC1640A-A (DCR Sense) at VIN = 12V. COUT = 2x Sanyo
2R5TPE330M9 || 2x 100µF, X5R, 6.3V, 1206; L = 0.47µH;
FSW = 300kHz
20A
10A
DC1640 F05
Figure 5. 10A to 20A to 10A Load Step Response of the
DC1640A-B (RSENSE) at VIN = 12V. COUT = 2x Sanyo
2R5TPE330M9 || 2x 100µF, X5R, 6.3V, 1206; FSW = 300kHz;
L = 0.44µH
dc1640af
4
DEMO MANUAL DC1640A
PARTS LIST
DEMO CIRCUIT 1640A-A (DCR SENSE)
ITEM
QUANTITY REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C1
Cap X7R 0.22µF 16V 10% 0603
AVX 0603YC224KAT2A
2
2
C3, C9
Cap X7R 0.1µF 16V 10% 0603
AVX 0603YC104KAT2A
3
1
C4
Cap X7R 0.01µF 16V 10% 0603
AVX 0603YC103KAT2A
4
1
C5
Cap C0G 100pF 50V 5% 0603
AVX 06035A101JAT2A
5
1
C6
Cap C0G 470pF 50V 10% 0603
AVX 06035A471KAT2A
6
1
C7
Cap X5R 4.7µF 16V 10% 0805
AVX 0805YD475KAT2A
7
3
CIN1, CIN2, CIN6
Cap X5R 22µF16V 10% 1210
Murata GRM32ER61C226KE20L
8
1
CIN4
Cap SVP 180µF 16V 30mΩ ESR
Sanyo 16SVP180MX
9
2
COUT1, COUT2
Cap X5R 100µF 6.3V 20% 1206
Murata GRM31CR60J107ME39L
10
2
COUT3, COUT4
Cap POSCAP 330µF 2.5V 20% 7343
Sanyo 2R5TPE330M9
11
1
D1
Diode Schottky 30V SOD323
Central Semi CMDSH-3TR
12
1
L1
Inductor 0.47µH
Würth Elektronik 744355047
13
1
Q1
MOSFET Power N-CH LFPAK
Renesas RJK0305DPB
14
1
Q2
MOSFET Power N-CH LFPAK
Renesas RJK0330DPB
15
1
R1
Res 100k 1/16W 5% 0603
Yageo RC0603JR-07100KL
16
2
R10, R11
Res 10 1/16W 5% 0603
Yageo RC0603JR-0710RL
17
2
R13, R17
Res 0 1/16W 0603
Yageo RC0603FR-070RL
18
1
R15
Res 13k 1/16W 1% 0603
Yageo RC0603FR-0713KL
19
1
R18
Res 137k 1/16W 1% 0603
Yageo RC0603FR-07137KL
20
1
R20
Res 2.2 1/16W 5% 0603
Yageo RC0603JR-072R2L
21
2
R21, R8
Res 10k 1/16W 1% 0603
Yageo RC0603FR-0710KL
22
2
R4, R9
Res 0 1/16W 0603
Yageo RC0603FR-070RL
23
1
R6
Res 15k 1/10W 1% 0603
Yageo RC0603FR-0715KL
24
1
R7
Res 2.15k 1/16W 1% 0603
Yageo RC0603FR-072K15L
25
1
RS1
Res 0.000 2512
Tepro RN5326
26
1
U1
IC LTC3833EUDC
Linear Technology LTC3833EUDC#PBF
Additional Circuit Components
1
0
C2, C8, C10
Cap 0603
OPT
2
0
CIN3
Cap SVP-F8
OPT
3
0
CIN5
Cap 1210
OPT
4
0
COUT5, COUT6
Cap 1206
OPT
5
0
Q3, Q4
MOSFET Power N-CH LFPAK
OPT
6
1
Q5
MOSFET N-CH 30-V (D-S) DPAK-TO252AA
Vishay SUD50N03-12P-E3
7
1
R22
Res Chip 10k 1/16W 1% 0603
Yageo RC0603FR-0710KL
8
1
R23
Res 0.01 2% 2010
IRC LRC-LRF2010LF-01-R010-G
9
0
R2, R3, R12, R14, R5, R16, R19 Res 0603
OPT
Hardware for Demo Board Only
1
10
E1 to E10
Testpoint Turret .094”
Mill-Max 2501-2-00-80-00-00-07-0
2
4
J1, J2, J3, J4
Jack Banana
Keystone 575-4
3
2
J5, J6
Conn BNC 5 Pins
Connex 112404
4
2
JP1, JP2
Shunt 2MM Center
Samtec 2SN-BK-G
5
2
JP1, JP2
Header 2MM Single Row 3 Pin
Samtec TMM-103-02-L-S
6
4
Stand-Off Nylon 0.50”
Keystone 8833 (Snap-On)
dc1640af
5
DEMO MANUAL DC1640A
PARTS LIST
DEMO CIRCUIT 1640A-B (RSENSE)
ITEM
QUANTITY REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C1
Cap X7R 1000pF 50V 5% 0603
AVX 06035C102JAT2A
2
2
C3, C9
Cap X7R 0.1µF 16V 10% 0603
AVX 0603YC104KAT2A
3
1
C4
Cap X7R 0.01µF 16V 10% 0603
AVX 0603YC103KAT2A
4
1
C5
Cap C0G 100pF 50V 5% 0603
AVX 06035A101JAT2A
5
1
C6
Cap C0G 470pF 50V 10% 0603
AVX 06035A471KAT2A
6
1
C7
Cap X5R 4.7µF 16V 10% 0805
AVX 0805YD475KAT2A
7
3
CIN1, CIN2, CIN6
Cap X5R 22µF16V 10% 1210
Murata GRM32ER61C226KE20L
8
1
CIN4
Cap SVP 180µF 16V 30mΩ ESR
Sanyo 16SVP180MX
9
2
COUT1, COUT2
Cap X5R 100µF 6.3V 20% 1206
Murata GRM31CR60J107ME39L
10
2
COUT3, COUT4
Cap Poscap 330µF 2.5V 20% 7343
Sanyo 2R5TPE330M9
11
1
D1
Diode Schottky 30V SOD323
Central Semi CMDSH-3TR
12
1
L1
Inductor 0.44µH
Cooper Bussmann FP1308R3-R44-R
13
1
Q1
MOSFET Power N-CH LFPAK
Renesas RJK0305DPB
14
1
Q2
MOSFET Power N-CH LFPAK
Renesas RJK0330DPB
15
1
R1
Res Chip 100k 1/16W 5% 0603
Yageo RC0603JR-07100KL
16
2
R10, R11
Res Chip 10 1/16W 5% 0603
Yageo RC0603JR-0710RL
17
1
R14
Res Chip 0 1/16W 0603
Yageo RC0603FR-070RL
18
1
R15
Res Chip 16.5k 1/16W 1% 0603
Yageo RC0603FR-0716K5L
19
1
R18
Res Chip 137k 1/16W 1% 0603
Yageo RC0603FR-07137KL
20
2
R2, R3
Res Chip 10 1/10W 1% 0603
Yageo RC0603FR-0710RL
21
1
R20
Res Chip 2.2 1/16W 5% 0603
Yageo RC0603JR-072R2L
22
2
R21, R8
Res Chip 10k 1/16W 1% 0603
Yageo RC0603FR-0710KL
23
2
R4, R9
Res Chip 0 1/16W 0603
Yageo RC0603FR-070RL
24
1
R6
Res Chip 15k 1/10W 1% 0603
Yageo RC0603FR-0715KL
25
1
RS1
Res Chip 0.002Ω 1W 1% 2512
Vishay WSL25122L000FEA
26
1
U1
IC LTC3833EUDC
Linear Technology LTC3833EUDC#PBF
Additional Circuit Components
1
0
C2, C8, C10
Cap 0603
OPT
2
0
CIN3
Cap SVP-F8
OPT
3
0
CIN5
Cap 1210
OPT
4
0
COUT5, COUT6
Cap 1206
OPT
5
0
Q3, Q4
MOSFET Power N-CH LFPAK
OPT
6
1
Q5
MOSFET N-CH 30-V (D-S) DPAK-TO252AA
Vishay SUD50N03-12P-E3
7
1
R22
Res Chip 10k 1/16W 1% 0603
Yageo RC0603FR-0710KL
8
1
R23
Res 0.01 2% 2010
IRC LRC-LRF2010LF-01-R010-G
9
0
R2, R3, R12, R14, R5, R16, R19 Res 0603
OPT
Hardware for Demo Board Only
1
10
E1 to E10
Testpoint Turret .094”
Mill-Max 2501-2-00-80-00-00-07-0
2
4
J1, J2, J3, J4
Jack Banana
Keystone 575-4
3
2
J5, J6
Conn BNC 5 Pins
Connex 112404
4
2
JP1, JP2
Shunt 2MM Center
Samtec 2SN-BK-G
5
2
JP1, JP2
Header 2MM Single Row 3 Pin
Samtec TMM-103-02-L-S
6
4
Stand-Off Nylon 0.50”
Keystone 8833 (Snap-On)
dc1640af
6
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation
that the interconnection of its circuits as described herein will not infringe on existing patent rights.
D
C
B
*
JP1
E8
R16
OPT
R19
OPT
VIN
C8
OPT
*
R14
*
R17
INTVCC
0
R4
470pF
1
-A (DCR SENSE)
-B (RSENSE)
ASSY
L1
R6
15K
2
WURTH 744355047 (0.47uH)
COILTRONICS FP1308R3-R44-R (0.44uH)
2. INSTALL SHUNTS ON JUMPERS AS SHOWN.
1. ALL RESISTORS ARE IN OHMS, 0603.
ALL CAPACITORS ARE IN MICROFARADS, 0603.
*
R15
C2
OPT
FSW = 300kHz
C6 100pF
0.01uF C5
C4
R5
OPT
NOTES: UNLESS OTHERWISE SPECIFIED
PLLIN
E7
E5
E4
1
2
3
EXTVCC
ON
OFF
RUN
TRK/SS
PGOOD
6
5
4
3
2
1
21
0.22uF
1000pF
C1
R18
137K
R8
10K
2.15K
OPT
R7
C10
OPT
SGND
RT
VRNG
ITH
TRKSS
VOSNS+
VOSNS-
U1
LTC3833EUDC
VOUT
S-
*
C1
*
R2
*
S+
R3
3
OPT
OPT
R12
0
OPT
R13
C9 2.2
0.1uF
16V
R21
10K
11
12
13
14
15
16
R20
INTVCC
PGND
BG
SW
TG
BOOST
20
VOUT
RUN
7
R1
100K
19
SNSEXTVCC
8
INTVCC
18
SNS+
MODE/PLLIN
9
A
17
PGOOD
VIN
10
0
R9
INTVCC
JP2
OPT
0
4
0
OPT
R17
DCM
CCM
MODE
R14
1
2
3
C7
4.7uF
16V
0805
C3
0.1uF
16V
4
4
OPT
10
R2,R3
D1
CMDSH-3
4
5
Q1
RJK0305DPB
Q2
RJK0330DPB
1
2
3
5
4
4
5
Q3
OPT
Q4
OPT
RS1
CIN1
22uF
16V
1210
VIN
5
*
L1
*
R7
S-
*
VOUT
R12
*
R13
S+
6
*
J5
2512
RS1
6
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
CUSTOMER NOTICE
13.0K
16.5K
R15
DCR SENSE
FILTER /
DIVIDER
CIN2
22uF
16V
1210
0.000 Ohm 2512, TEPRO RN5326
0.002 Ohm 2512, VISHAY WSL25122L000FEA
1
2
3
5
1
2
3
5
1
2
3
3
5
4
3
2
2
COUT2
100uF
6.3V
1206
MIKE S.
APP ENG.
SCALE = NONE
NC
PCB DES.
APPROVALS
COUT3
330uF
2.5V
7343
CIN5
OPT
1210
DATE:
N/A
SIZE
R22
10K
E10
E9
GND
PULSE GEN
COUT6
OPT
1206
TECHNOLOGY
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
LOAD STEP CIRCUIT
R23
0.01
2010
GND
VOUT
1.5V / 20A
VIN-
GND
DATE
9/27/10
7
LTC3833EUDC
DEMO CIRCUIT 1640A-A/B
9/27/10
IC NO.
8
SHEET 1
OF
1
2
REV.
HIGH EFFICIENCY STEP-DOWN DC-DC CONVERTER
TITLE: SCHEMATIC
1
1
Q5
MIKE S.
VIN
4.5V - 14V
VIN+
8
APPROVED
ONLY APPLY LOAD
FROM J3 TO J4
J4
J3
E6
180uF
16V
J2
J1
E3
VO_SNS-
VO_SNS+
+ CIN4
COUT5
OPT
1206
OPT
SVP-F8
+ CIN3
COUT4
330uF
2.5V
7343
VOUT
+
VOUT
CIN6
22uF
16V
1210
E2
E1
PRODUCTION FAB
2
-
REVISION HISTORY
DESCRIPTION
REV
ECO
7
SUD50N03-12P
+
R11
10
LOAD STEP
J6
10mV / A
5% DUTY CYCLE MAX
1
COUT1
100uF
6.3V
1206
R10
10
5
4
3
2
2
3
1
D
C
B
A
DEMO MANUAL DC1640A
SCHEMATIC DIAGRAM
dc1640af
7
DEMO MANUAL DC1640A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
dc1640af
8
Linear Technology Corporation
LT 1210 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2010
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